I suggest that you try PhoneMagic demo (good for 30 days) in the link I provided. You will experience what I am talking about once you try using it.
When using PhoneMagic, you can use your fingers to tap on the large buttons to look-up an address.
T9-style look up works this way: if you are looking for Bob's number, tap the (ABC) button once, (MNO) button once, and (ABC) button once again. In short, you spelled "BOB" by tapping once the button where the letter is located. So for Mary, tap (MNO), (ABC), (PQRS), (WXYZ) and Mary's address/number will be shown.
(Note: The buttons are configured similar to telephone buttons with several alphabetically arranged letters on each button).
Once you get to an address entry, tap "dial" and you will have a choice of dialing any of the numbers there thru your cellphone (paired by bluetooth or infrared), or making a tone dial by putting the T3 speaker near the mouthpiece of a conventional touch tone phone.
Try PhoneMagic, and you'll probably find it as a very convenient address book replacement application. Its main advantage is that you don't need to use a stylus, or to even open the T3 slider, to look up addresses.